Parking assist system

ABSTRACT

In one aspect, the invention is directed to a parking assist system for a vehicle, wherein the parking assist system has two modes of operation. In a first mode a first overlay is added to an image of a rearward field of view displayed to the vehicle driver. The first overlay includes a representation of a target parking position. In a second mode a second overlay is added to the field of view displayed to the vehicle driver. The second overlay includes a representation of a projected path for the vehicle based on a current vehicle steering angle, and a representation of a target path segment for the vehicle.

FIELD OF THE INVENTION

The present invention relates to a parking assist system for use invehicles.

BACKGROUND OF THE INVENTION

Parking assist systems are currently available only on certain luxuryvehicles, and are typically relatively complex systems that are eitherentirely or semi-autonomous, capable of steering and/or driving thevehicle into a parking spot. Such systems typically require significantprocessing power in order to determine a suitable path to follow duringthe parking maneuver. Such systems can be relatively expensive.

It would be advantageous if a parking assist system were available thatrequired relatively less processing power, that was relatively simpler,and was relatively less expensive than some systems of the prior art.

SUMMARY OF THE INVENTION

In a first aspect, the invention is directed to a parking assist systemfor a vehicle, wherein a target parking position overlay is added to animage of a field of view of the camera displayed to the vehicle driver.

In a particular embodiment of the first aspect, the parking assistsystem includes a camera mounted to the vehicle and having a rearwardfield of view, a display in the vehicle connected to the camera andconfigured to display an image of the field of view, and a controllerconfigured to add an overlay to the image of the field of view. Theoverlay includes a representation of a target parking position.

In a second aspect, the invention is directed to a parking assist systemfor a vehicle, that is configured to:

select a target path for the vehicle driver to follow while parking thevehicle,

to inform the driver of the vehicle's projected path based on thevehicle's steering angle,

and to inform the driver of whether the projected path matches thetarget path.

In a particular embodiment of the second aspect, the parking assistsystem includes a camera mounted to the vehicle and having a rearwardfield of view, a display in the vehicle connected to the camera andconfigured to display an image of the field of view, and a controllerconfigured to add an overlay to the image of the field of view. Theoverlay includes a representation of a projected path for the vehiclebased on a current vehicle steering angle, and a representation of atarget path for the vehicle.

In a third aspect, the invention is directed to a parking assist systemfor a vehicle, wherein the parking assist system has two modes ofoperation. In a first mode a first overlay is added to an image of arearward field of view of the camera displayed to the vehicle driver.The first overlay includes a representation of a target parkingposition. In a second mode a second overlay is added to the field ofview displayed to the vehicle driver. The second overlay includes arepresentation of a projected path for the vehicle based on a currentvehicle steering angle, and a representation of a target path segmentfor the vehicle.

In a particular embodiment of the third aspect, the parking assistsystem includes a camera mounted to the vehicle and having a rearwardfield of view, a display in the vehicle connected to the camera andconfigured to display an image of the field of view, and a controllerconfigured to operate the parking assist system in two operating modes.In a first operating mode the controller is configured to add a firstoverlay to the image of the field of view, wherein the first overlayincludes a representation of a target parking position. In a secondoperating mode the controller is configured to add a second overlay tothe image of the field of view, wherein the second overlay includes arepresentation of a projected path for the vehicle based on a currentvehicle steering angle, and a representation of a target path segmentfor the vehicle.

In a fourth aspect, the invention is directed to a parking assist systemfor a vehicle, wherein the parking assist system selects a plurality oftarget path segments for the vehicle to follow to park in a targetparking spot, wherein each target path segment involves the vehiclehaving steering wheels pointed straight or at full lock.

In a particular embodiment of the fourth aspect, the parking assistsystem includes a camera mounted to the vehicle and having a rearwardfield of view, a display in the vehicle connected to the camera andconfigured to display an image of the field of view, and a controllerconfigured to select a plurality of target path segments for the vehicleto follow to park in a target parking spot. Each target path segmentinvolves the vehicle having the steering wheels pointed straight or atfull lock.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described by way of example only withreference to the attached drawings, in which:

FIG. 1 is a schematic illustration of a parking assist system inaccordance with an embodiment of the present invention;

FIG. 2 is a view of an image of a field of view of the camera on adisplay that is part of the parking assist system shown in FIG. 1;

FIG. 3 is a view of an image of a field of view of the camera on thedisplay shown in FIG. 3, with the parking assist system in a parkingspot locator mode;

FIG. 4 is a view of an image of a field of view of the camera on thedisplay shown in FIG. 3, with the parking assist system in the parkingspot locator mode, after the vehicle has traveled past a target parkingspot;

FIG. 5 is a view of an image of a field of view on the display shown inFIG. 3, with the parking assist system in the parking spot locator mode,after the vehicle has backed up to a suitable position to park in thetarget parking spot;

FIG. 6 is a view of an image of a field of view on the display shown inFIG. 3, with the parking assist system in a parking guidance mode,showing the alignment between the projected path of the vehicle with afirst target path segment for the vehicle;

FIGS. 7 a-7 d are views of an image of a field of view on the displayshown in FIG. 3, with the parking assist system in the parking guidancemode, illustrating the progression of the vehicle along the first targetpath segment;

FIGS. 8 a-8 c are views of an image of a field of view on the displayshown in FIG. 3, with the parking assist system in the parking guidancemode, showing the progression towards alignment between the projectedpath of the vehicle with a second target path segment for the vehicle;

FIGS. 9 a and 9 b are views of an image of a field of view on thedisplay shown in FIG. 3, with the parking assist system in the parkingguidance mode, illustrating the progression of the vehicle along thesecond target path segment;

FIGS. 10 a-10 d are views of an image of a field of view on the displayshown in FIG. 3, with the parking assist system in the parking guidancemode, showing the progression towards alignment between the projectedpath of the vehicle with a third target path segment for the vehicle;

FIG. 11 is a view of an image of a field of view on the display shown inFIG. 3, with the parking assist system in the parking guidance mode,showing the vehicle having nearly completed the third target pathsegment for the vehicle; and

FIG. 12 is a view of an image of a field of view on the display shown inFIG. 3, with the parking system in the parking guidance mode, whereinthe vehicle is parking in a perpendicular parking spot.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made to FIG. 1, which shows a parking assist system 10 foruse in a vehicle 11, in accordance with an embodiment of the presentinvention. The parking assist system includes a camera 12, a controller14 and a display 16. The camera 12 is positioned on the vehicle 11 forrearward viewing and has a field of view generally shown at 18. Thecontroller 14 communicates with the camera 12 and sends an image 20 ofthe field of view 18 (FIG. 2) to the display 16, which is positioned inthe vehicle cabin. The display 16 is positioned to display the image 20of the field of view 18 to the vehicle driver.

When the vehicle driver wants to use the parking assist system 10 (FIG.1), he or she presses a button in the interior of the vehicle 11, whichactivates the parking assist system 10 in a first mode, which is aparking spot locator mode. When in the parking spot locator mode, thecontroller 14 adds an overlay 22 (FIG. 3) to the image 20, which assiststhe driver in finding a suitable parking spot for the vehicle 11 (FIG.1). The overlay 22 (FIG. 3) includes a rectangle 24 which is arepresentation of a target parked position which is offset a selecteddistance behind and a selected distance laterally from the vehicle 11(FIG. 1). The size of the rectangle 24 (FIG. 3) preferably representssubstantially the length and further preferably represents substantiallythe width of the vehicle 11 (FIG. 1).

The overlay 22 (FIG. 3) also includes a line 26 extending along theoutside edge (shown at 28) of the rectangle 24 (ie. the side edge of therectangle 24 that faces outwardly from the parking spot).

The line 26 extends a selected distance forward of the rectangle 24 anda selected distance rearward of the rectangle 24 and assists the driverof the vehicle 11 in lining up the vehicle 11 to be parallel to theparking lane.

With the overlay 22 shown on the image 20, the driver drives along theroad until he or she finds a potential parking spot, shown at 30 in FIG.4. In the exemplary embodiment shown in the figures, the driver droveforward to find the potential parking spot 30. As shown in FIG. 4, thevehicle 11 has overshot the potential parking spot 30 and so the forwardedge of the rectangle 24 is too far forward, overlapping with thevehicle (shown at 32) that is forward of the potential parking spot 30.Having driven too far forward, the driver may put vehicle 11 (FIG. 1)into reverse gear in order to back up to superimpose the rectangle 24 onthe potential parking spot 30.

When the vehicle is in reverse, a representation 34 of the projectedpath of the vehicle is added to the included in the overlay 22 that isprovided with the image 20 shown on the display 16. The representation34 is based on the steering angle of the vehicle and is updated as thesteering angle changes.

The representation 34 includes several features such as lateral edgelines 36 and distance markers 38. The lateral edge lines 36 correspondto the lateral edges of the vehicle. The distance markers 38 eachcorrespond to a selected distance behind the vehicle, preferably inuniform increments.

As shown in FIG. 5, the vehicle 11 (FIG. 1) has backed up sufficientlyto superimpose the rectangle 24 on the potential parking spot 30. Oncein this position, the driver can see that the vehicle 11 (FIG. 1) hassufficient room to fit in the parking spot 30. It is optionally possiblefor the length of the rectangle 24 to be the length required by thevehicle to fit in the parking spot instead of simply representing thelength of the vehicle 11 (FIG. 1) itself. As will be understood by oneskilled in the art, the length required by the vehicle (FIG. 1) to parkin a spot is some amount longer than the length of the vehicle (FIG. 1)itself.

Once the driver has decided that the parking spot 30 (FIG. 5) issuitable, he or she may press another button on the dashboard toactivate the parking assist system 10 (FIG. 1) in a parking guidancemode, as shown in FIG. 6.

In the parking guidance mode, the parking assist system 10 (FIG. 1)determines a target path for the vehicle 11 to follow in order to parkin the spot delineated by the rectangle 24 (FIG. 6) at the time that theparking guidance mode was initiated.

When in the parking guidance mode, two representations are shown on thedisplay 16. One is the aforementioned representation 34 of the vehicle'sprojected path at the current steering angle. The other is arepresentation shown at 40 a of a segment of the target path to reachthe parking spot delineated by the rectangle 24 (FIG. 5).

Initially, the driver turns the vehicle's steering wheel until theprojected path representation 34 of the vehicle substantially alignswith the target path segment representation 40 a. When they are suitablyaligned, the parking assist system 10 may notify the driver that he/shecan proceed to back the vehicle up along the target path. Alternatively,the alignment of the representations 34 and 40 a visually on the display16 may itself be considered notification to the driver that theprojected path suitably matches the target path.

Referring to FIGS. 7 a, 7 b, 7 c and 7 d, as the driver backs thevehicle up progressively along the target path segment, a distal portion42 of the target path representation 40 a change from one colour toanother, shortening the length of the proximal portion 44 of therepresentation 40 a that remains in the first colour. This gives thedriver an indication of how much of the target path segment remains tobe driven before another phase of the parking maneuver is to be made.

Once the vehicle has driven the entire target path segment, the parkingassist system 10 selects the next segment of the target path for thevehicle to follow, and represents it on the display 16 as therepresentation 40 b shown in FIG. 8 a. The second target path segmentrepresentation 40 b guides the driver in the turn-in phase of theparking maneuver. At the point in time shown in FIG. 8 a, the vehicle'ssteering wheels are still pointed straight since the first target pathsegment which was just completed was a straight segment. Thus, at thepoint in time shown in FIG. 8 a, the driver's projected path representedat 34 is misaligned with the second target path segment represented at40 b.

As the driver turns the steering wheel to align the vehicle's projectedpath with the target path segment, the projected path representation 34becomes progressively aligned with and superimposed with the target pathsegment representation 40 b, as shown in FIG. 8 b. After the driverturns the steering wheel sufficiently, the vehicle's projected path isaligned with the vehicle's target path segment, as shown by therepresentations 34 and 40 b in FIG. 8 c. The target path segmentillustrated in FIGS. 8 a, 8 b and 8 c may be the path at full wheel lock(ie. at the maximum steering angle the vehicle is capable of).

FIGS. 9 a and 9 b show the progress of the vehicle along the secondtarget path segment. Once the vehicle has moved along the entire secondtarget path segment, the parking assist system 10 selects the next (ie.third) target path segment for the vehicle to follow, which isrepresented in FIG. 10 a at 40 c. The third target path segment is thetuck-in phase of the parking maneuver and requires that the driver turnthe steering wheel to the opposite limit. FIGS. 10 a-10 d illustrate thedriver turning the wheel to bring the projected path into alignment withthe third target path segment.

Once the projected path and third target path segment are aligned, thedriver backs the vehicle up along the third target path segment. FIG. 11illustrates the vehicle having completed almost all of the third targetpath segment. After the third target path segment is completed, thedriver has completed the entire parking maneuver. Optionally he/she candrive forward if desired to adjust the spacing between the driver'svehicle and the vehicles in front and behind.

It will be noted that the parking maneuver includes three phases, abackup phase wherein the vehicle is backed up in a straight line (withthe wheels pointing straight), a turn-in phase wherein the vehicle isbacked up at full wheel lock in one direction, and a tuck-in phasewherein the vehicle is backed up at full wheel lock in the otherdirection. Providing target path segments wherein the wheels are pointedstraight or are at full lock simplifies the process of aligning theprojected path with the target path segment, and simplifies keeping thevehicle along the target path segment.

While backing the vehicle up along a target path segment, if the driverfor some reason veers off the target path by more than a selectedamount, the parking assist system 10 notifies the driver, and optionallyaborts the parking maneuver.

Optionally, the parking assist system 10 can permit the driver to selectwhether the parking spot is to the left of the vehicle (as shown in thefigures) or to the right of the vehicle. For a parking spot on the rightof the vehicle, the turn-in and tuck-in phases would be mirror images ofthe turn-in and tuck-in phases illustrated in FIGS. 8 a-11.

It will be understood that the three target path segments need not allbe the same length.

It will be noted that the rectangle 24 (FIG. 5) is at a fixed positionbehind and to the side of the vehicle. The target path for the parkingmaneuver is thus the same each time the vehicle is to be parked althoughit may be mirrored in the optional embodiment wherein the parking assistsystem 10 permits selecting a parking spot on the other side (ie. theright side) of the vehicle. As a result of the consistency in theparking maneuver, the parking maneuver need not be recalculated eachtime the vehicle uses the parking assist system 10. This permits theparking assist system 10 to operate using relatively inexpensive controlhardware and software.

In the above description, the in-cabin display 16 was used as thehuman/machine interface and provided the driver with instructionsvisually/graphically for driving the vehicle into a parking spot. It ispossible to provide instructions to the driver by other means inaddition to or instead of using the in-cabin display 16. For example,the human/machine interface could include a speaker (eg. from thevehicle's sound system) and could emit audible messages to the drivervia the speaker. Such messages could be instructions in any language,such as English. For example, an instruction could be given audibly toturn the vehicle steering wheel to a selected position (eg. full lock tothe left). It will be noted that such an instruction would in effectinform the driver of the target path for the vehicle. In addition to theaudible messages, or instead of them, a chime or a beep could be emittedat points in the parking process where the driver is supposed to carryout a new maneuver, to let the driver know that he/she is off course, tolet the driver know that he/she is on course (ie. that the projectedvehicle path matches the target path), or for any other suitablepurpose.

In the above description a method and system were described for parallelparking into a parking spot. It is also possible for an embodiment ofthe invention to be provided for parking into a perpendicular parkingspot 30 (see FIG. 12). A perpendicular parking spot 30 is a parking spotthat is perpendicular to the direction of travel of the vehicle whendriving by. Perpendicular parking spots are typically used in parkinglots for malls, office buildings and the like. In the position shown inFIG. 12, the vehicle has already completed some portion of the parkingprocess and is backing into the parking spot 30.

While the above description constitutes a plurality of embodiments ofthe present invention, it will be appreciated that the present inventionis susceptible to further modification and change without departing fromthe fair meaning of the accompanying claims.

1. A parking assist system for a vehicle, comprising: a camera mountedto the vehicle so as to receive a rearward scene; a display in thevehicle connected to the camera and configured to display an image ofthe rearward scene; a controller operable to add an overlay to the imageof the rearward scene, wherein the overlay includes a representation ofa target parking position; and wherein at least one of (a) thecontroller is operable to select a target path for the vehicle, toinform the driver of a projected path for the vehicle based on a currentvehicle steering angle, and to inform the driver of whether theprojected path substantially matches the target path, and (b) thecontroller is operable to select a plurality of target path segments forthe vehicle to follow, wherein each target path segment involves thevehicle having steering wheels pointed straight or at full lock.
 2. Aparking assist system as claimed in claim 1, wherein the representationhas a length that represents generally the length of the vehicle.
 3. Aparking assist system as claimed in claim 2, wherein the representationhas a width that represents generally the width of the vehicle.
 4. Aparking assist system as claimed in claim 1, wherein the overlay is afirst overlay and wherein the controller is operable to operate theparking assist system in two operating modes which are selectable by auser, wherein in a first operating mode the controller is operable toadd the first overlay to the image of the rearward scene, and wherein ina second operating mode the controller is operable to add a secondoverlay to the image of the rearward scene, wherein the second overlayincludes a representation of a projected path for the vehicle based on acurrent vehicle steering angle, and a representation of a target pathsegment for the vehicle.
 5. A parking assist system as claimed in claim1, wherein the target parking position is parallel to a direction oftravel of the vehicle.
 6. A parking assist system as claimed in claim 1,wherein the target parking position is perpendicular to a direction oftravel of the vehicle.
 7. A parking assist system for a vehicle,comprising: a camera mounted to the vehicle so as to receive a rearwardscene; a human/machine interface including a display operable to displayan image of the rearward scene; and a controller operable to select atarget path for the vehicle, to inform the driver of a projected pathfor the vehicle based on a current vehicle steering angle, and to informthe driver of whether the projected path substantially matches thetarget path.
 8. A parking assist system as claimed in claim 7, whereinthe controller is operable to add an overlay to the image of therearward scene, wherein the overlay includes a representation of aprojected path for the vehicle based on a current vehicle steeringangle, and a representation of a target path for the vehicle.
 9. Aparking assist system as claimed in claim 8, wherein when the vehicle ismoving along the target path the overlay includes a representation ofthe progress of the vehicle on the target path.
 10. A parking assistsystem as claimed in claim 7, wherein the representation of theprojected path of the vehicle has a width that represents substantiallythe entire width of the vehicle.
 11. A parking assist system as claimedin claim 7, wherein the controller informs the driver of the target pathsegments via a speaker.
 12. A parking assist system as claimed in claim11, wherein the controller informs the driver of the target pathsegments by instructing the driver to turn the steering wheel of thevehicle to a selected position.
 13. A parking assist system as claimedin claim 7, wherein the controller informs the driver of whether theprojected path substantially matches the target path via a speaker. 14.A parking assist system for assisting in the completion of a parkingmaneuver on a vehicle, comprising: a camera mounted to the vehicle so asto receive a rearward scene; a display in the vehicle connected to thecamera and operable to display an image of the rearward scene; and acontroller operable to select a plurality of target path segments forthe vehicle to follow, wherein each target path segment involves thevehicle having steering wheels pointed straight or at full lock.
 15. Aparking assist system as claimed in claim 14, wherein the plurality oftarget path segments is three target path segments, including a firsttarget path segment in which the vehicle is driven straight rearwardly,a second target path segment in which the vehicle is driven rearwardlywith the steering wheels at full lock in one direction, and a thirdtarget path segment in which the vehicle is driven rearwardly with thesteering wheels at full lock in the opposite direction.
 16. A parkingassist system as claimed in claim 15, wherein the length of each targetpath segment remains constant from one parking maneuver to another. 17.A parking assist system as claimed in claim 14, wherein the controllerinforms the driver of the target path segments via the display.
 18. Aparking assist system as claimed in claim 14, wherein the controllerinforms the driver of the target path segments via a speaker.
 19. Aparking assist system as claimed in claim 14, wherein, when the vehicleis moving along a target path, the overlay includes a representation ofthe progress of the vehicle on the target path.
 20. A parking assistsystem as claimed in claim 14, wherein the overlay includes arepresentation of a projected path of the vehicle, and wherein therepresentation of the projected path has a width that representssubstantially the entire width of the vehicle.